My project sheds new light on the intersection between Dutch Christian Hebraism and Jewish apologetic writing, and situates Saul Levi Morteira (c. 1596-1660), the rabbi and teacher of Baruch Spinoza (1632-77), as a bridge between rabbinic thought in the nascent Dutch Republic and the political concepts of Spinoza. The project consists of a translation and scholarly introduction to an unedited work composed in Spanish by Morteira around 1630, Obstáculos y oposiciones contra la religión christiana en Amsterdam (Arguments Against the Christian Religion in Amsterdam). I examine this work as a rabbinic manifestation of the respublica Hebraeorum (Hebrew republic) genre that reflects Morteira's awareness of (and possible participation in) early seventeenth century philosophical dialogues, and that speaks to his religious agenda by expressing a democratic motif that influenced the radical thought of Spinoza.